feat(console): persist the output zoom level across launches

The console zoom (s_console_zoom) was a plain static reset to 1.0 each launch,
unlike the sibling toggles. Wire it through Settings (console_zoom float),
restored into the static at startup in the App ctor and written back via the
existing post-render diff-and-save. Loading clamps to [0.25, 4.0] (also
catching NaN) so a corrupt value can't feed the scanline divisor.

Verified: seeding console_zoom=1.5 survives a relaunch and the console text
renders larger.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/config/settings.h

@@ -195,6 +195,8 @@ public:
     void setConsoleLineAccents(bool v) { console_line_accents_ = v; }
     bool getConsoleTextColor() const { return console_text_color_; }
     void setConsoleTextColor(bool v) { console_text_color_ = v; }
+    float getConsoleZoom() const { return console_zoom_; }
+    void setConsoleZoom(float v) { console_zoom_ = v; }
 
     // Hidden addresses (addresses hidden from the UI by the user)
     const std::set<std::string>& getHiddenAddresses() const { return hidden_addresses_; }
@@ -491,6 +493,7 @@ private:
     bool scanline_enabled_ = true;
     bool console_line_accents_ = true;   // left color accent bars in console output
     bool console_text_color_ = true;     // per-channel text coloring in console output
+    float console_zoom_ = 1.0f;          // console output font zoom factor
     std::set<std::string> hidden_addresses_;
     std::set<std::string> favorite_addresses_;
     std::map<std::string, AddressMeta> address_meta_;